1. Field of the Invention
The present invention is related to a hidden screw-pressing structure for a pipe connector, and especially to a screw-pressing structure wherein a cover compresses a spring when in screwing in for tightening, so that the spring pushes a "C" shaped engaging member to render it to abut at an end of the connector against a diameter-reducing wall, so that the inner wall of the "C" shaped engaging member creates diameter reducing function and thus screw-pressing the external wall of a pipe to be connected.
2. Description of the Prior Art
Pipe connectors have been widely used in the cases requiring connection of pipes in the markets, for example, of those pipes made of metal, such as plumbing pipes, electric wire pipes, pipes for exhibition shelves and pipes for bicycle frames etc., the connectors and the pipes to be connected do not have to be undetatchably welded or locked for the sake of convenience of detatching for maintenance, therefore, movable locking modes are adapted and are widely used in the art.
However, people who assemble pipe connectors with pipes in a movable locking mode mostly use the pipe connectors having internal screw threads and the pipes to be connected having external screw threads, so that the internal and external screw threads can be mutually engaged, the defect of this mode is that the external screw threads tend to be exposed and make a trouble of ugliness, and they are subjected to wetting and rusting and blocking thereby, particularly in those cases requiring high quality as well as as good appearance, manufacturers hate to see such defect.
And more, such pipe connectors and pipes assembled with internal screw threads and external screw threads must be connected or disconnected by using wrenches, and these wrenches must be those having fitted engaging heads for locking and unlocking just like a polygonal nut; however, requirement of wrenches for locking and unlocking has already been countrary to the principle of simpliness and easiness, and to form a polygonal nut shape for the appearance of the pipe connectors and pipes for locking and unlocking is a measure against requirement of good appearance of the consumers in the markets.